PowerPoint Presentation sensation and perception

SENSATION AND PERCEPTION

KEY POINTS

• Distinguish between sensation and perception
• Psychophysics: absolute threshold and difference threshold
• Identify each major sensory system, their receptors, and type of sensory information each receives
• Perception: selection, organization and interpretation

Sensation

• Input of sensory information
• Process of receiving, converting, and transmitting information from the outside world

Sensory Systems

• Vision
• Hearing
• Smell (olfaction)
• Taste (gustation)
• Vestibular sense (balance)
• Kinethesis (body movement)
• Touch (pressure, pain, temperature)

Vision

• Visual receptor cells located on retina:rods for night vision and cones for color vision
• The eye captures light and focuses it on the visual receptors, which convert light energy to neural impulses sent to the brain

Hearing

• Audition (hearing) occurs via sound waves, which result from rapid changes in air pressure caused by vibrating objects
• Receptors located in the inner ear (cochlea) tiny hair cells that convert sound energy to neural impulses sent along to brain

Smell and Taste

• Olfaction (smell) receptors are located at top of nasal cavity
• Gustation - (taste) receptors are taste buds on tongue. Four basic tastes: sweet, salty, sour and bitter

Body Senses

• Vestibular sense (sense of balance) results from receptors in inner ear
• Kinethesis - (body posture, orientation, and body movement) results from receptors in muscles, joint and tendons
• Skin senses detect touch (pressure, temperature and pain)

Processing

• Sensory reduction - filtering and analyzing of sensations before messages are sent to the brain
• Transduction - process of converting receptor energy into neural impulses the brain can understand
• Adaptation- decreased sensory response to continuous stimuli

Psychophysics

• Study of the relationship between the physical properties of stimuli and a person’s experience of them
• Absolute threshold - minimum amount of energy we can detect
• Difference threshold - (jnd) the smallest change in a stimulus we can detect

Perception

• “…a constructive process by which we go beyond the stimuli that are presented to us and attempt to construct a meaningful situation”.

Perceptual Processing

• Top-down: perception is guided by higher-level knowledge, experience, expectations, and motivations
• Bottom-up: perception that consists of recognizing and processing information about the individual components of the stimuli

Perception-Key Concepts

• Selection
• Organization
• Interpretation
• Subliminal perception and ESP

1. Three Major Factors of Selection

• Selective attention
• Feature detectors
• Habituation

2. Organization

• Form (Gestalt)
• Constancy(size, shape, color, brightness)
• Depth
• Color

Gestalt Principles

• Rules that summarize how we tend to organize bits and pieces of information into meaningful wholes

Gestalt Psychology: Form

• figure ground
• proximity
• closure
• contiguity
• similarity

Constancy

• Size constancy
• Shape constancy
• Color constancy
• Brightness constancy

3. Four Major Factors of Interpretation

• Perceptual adaptation
• Perceptual set
• Individual motivation
• Frame of reference

Subliminal Perception

• Stimuli that occur below the threshold of our conscious awareness but have a weak, if any effect on behavior

4. Extrasensory Perception (ESP)

• Alleged perception in the absence of sensory data
• Types of ESP - telepathy, precognition, clairvoyance, and psychokinesis